Ravers at the Aquamarine Open Air Festival in Kirzhach, 80 kilometres northeast of Moscow, began seeking medical help days after the show, complaining of eye and vision problems.

"They all have retinal burns, scarring is visible on them. Loss of vision in individual cases is as high as 80%, and regaining it is already impossible," Kommersant quoted a treating ophthalmologist as saying.

Partygoers say heavy rains forced organisers to erect massive tents for the all-night dance party. The damage seems to have been caused when laser beams that were intended for outdoor use to illuminate the sky, were somehow turned or reflected onto the crowd.

People always say they fell out of their chair when they actually didn't. Well.. I actually did. I was teetering precariously on the back two wheels of my rollychair when I read this headline on BoingBoing. I lost my balance, grabbed my desk, and almost brought the whole thing down on top of me. Fortunately, my desk, laden as it is, weighs more than I do.